Electromagnetic apparatus



a M. 0. TROY.

ELECTROMAGNETIC APPARATUS.

APPLICATION FILED-FEB. 3. 1919.

Patnted Jan. 11,1921.

l3 1 I [o /6 4 15 .l' Inventor 25 H] Matthew OfTros,

His .fittorneg.

UNITED STATES" PATENT OFFICE. -n'rmrnwO-iriiom or rrm'srmm), MASSACHUSETTS, AssreNoR r0 TRIO COMPANY, A CORPORATION or NEW Yonx.

GENERAL ELEC- ELECTROMAGNETIC APPARATUS.

Specification of Letters Patent. Pate t d J .1 19

Application .filed February a, 1919. Serial No. 274,757.

To all whom it may concern Be it known that I, MATTHEW O. TROY, a

citizen of the United. States, residing at Pittsfield, in the county of Berkshire, State of 'Massachusetts, have invented certain new and useful Improvements in Electromagnetic Apparatus, of which the following is tion relates to cores and core parts of electromagnetic ,ap aratus.

Objects 0 my invention are to provide a novel core for electromagnetic apparatus, a novel core. part,yan'da novel method of mak ing core parts for electromagnetic apparatus, wherebythe core operating losses and the waste of material are less than heretofore.

"In'the practice of my invention strip (preferably having a width equal to the depth of the core part 'to be produced) is cut from a rolled sheet of magnetic material, such strip extending in the direction of the rolling of the sheet. To use economically the material the strip is bent back on itself at a plurality of substantially uniformly spaced points throughout its length, until substantially solid block of close convolutions of the strip of magnetic material is produced, alternate convolutions at each end of the block projecting beyond intermediate convolutions. -A core according to my invention is assembled from a number of blocks produced in this manner, each, however, of a close] convoluted strip of material, these blocks orming the legs and yokes (and any other parts there may be) of the core with the projecting convolutions of each" block interleaving with the projecting convolutions of the adjacent block. I prefer to employ strips of magnetic material which eX- tend in a direction substantially parallel to the general direction of. the crystal structure or grain thereof, since this results in the magnetic flux traversing the core with a minimum of losses.

My invention will be better understood from the accompanying drawings and the following description, in which I have illustrated and described in some detail the best embodiment of my invention, of which I am now aware. Figure 1 illustrates very simply in outline a stationary transformer or reactor embodying my invention. Fig. 2 is a disassembled view in perspective of the core of the device of Fig. 1. Fig. 3 is an edge' view of one of the core or yoke portions of F 1g. 2. v I I The transformer or reactorof Fig.1 comprises a rectangular core 10 of magneticmaterial, on the two parallel legs on which are ,placed the windings 11 and12. Yoke members 13 and 14c connecttheadjacentends of the leg members 15 and 16. V I i Figs. 2 and 3 disclose particularly the construction ofthe legs and yokes'of Fig.1- It will be observed, for exam-plefthat the leg 15, orblock forming apart of the core of the electromagnetic apparatus of Fig. 1, com

prises a single strip of magnetic -;material so; closely convoluted as to provide a substan tially solid block. Alternate convolutions 2( "project equal distances beyond intermediate convolutions and terminate insubstantially a single plane which is at right angles to the length of the block. This appears from both Figs. 2 and 3. The core 10 is built up of four such blocks, 13, 14, 15 and 16, differing only in size as may be required. The four blocks are arranged together in the form of a rectangle as more clearly appears from Fig. 1, the projecting convolutions of adjacent blocks being interleaved as is clearly indicated in Fig. 2. Preferably the strips are so procured or so chosen, that the grain of the strip forming each block extends in the direction of the length of the strip, whereby the magnetic flux traverses the material of the core substantially in the direction of the grain of the material. As before indicated, this makes for minimum losses in the core.

The preferred method of my invention consists in the following: I start with a strip of magnetic material of the width 24 (see Fig. 2) equal to the depth of the core part to be produced. Preferably a strip is procured, or chosen in which the grain of the material extends in the, direction of the length of the strip. This strip is then bent back on itself at a pluralit of points 25, preferably uniformly space apart, to provide a block of a plurality of layers. To secure a strip in which the grain extends inthe direction of the length of the strip, I prefer to add to the method above described as the first step thereof, cutting from rolled sheets of magnetic material a strip extending in the direction of the rolling.

While I have illustrated and described in some detail the best embodiment of my invention, of which I am now aware, it will be understood that this embodiment is illustrated and described merely for better disclosing my invention, and that my invention following claims.

What I claim as new and desire to secure by Letters Patent of the United States, is

1. A closely convoluted strip of magnetic material forming a part of a core of an electromagnetic apparatus, the grain of the material extending in the direction of the length I of the strip.

2. A block of a closely convoluted strip of magnetic material forming a part of a core of an electromagnetic apparatus, some of the convolutions projecting beyond others at one end of the block. v

3. A block of a closely convoluted strip of magnetic material forming a part of a core of an electromagnetic apparatus, alternative convolutions projecting equal distance beyond the intermediate convolutions at one end of the block and terminating in substantially the same plane at right angles to the length of said block.

4. A block of a closely convoluted strip of magnetic material forming a part of a core of an electromagnetic apparatus, convolu-. V t1ons projecting beyond intermediate convocomprising adjacent blocks, each of a closely convoluted strip of material with convolutions projecting beyond intermediate convolutions at one end of the respective block, the projecting convolutions of the said blocks being interleaved.

6. The method of making a core part for electromagnetic apparatus, which consists in bending back on itself at a plurality of points to provide a plurality of layers, a strip of magnetic material in which the grain extends in the direction of the length of the strip. 7 I

7. The method of making a core part for electromagnetic apparatus, which consists in cutting from rolled sheets of magnetic material a strip extending in the direction of vthe rolling, and bending the strip back on itself at a plurality of points to providea plurality of layers.

In wltness whereof, I have hereunto set my hand this 30th day of January, 1919.

MATTHEW o. TROY. 

